Undercarriage assembly for a vehicle

ABSTRACT

An undercarriage assembly for a work vehicle includes first and second roller frame assemblies, one on each side of the vehicle, an idler wheel assembly connected to one end of each roller frame assembly, and a drive wheel connected to the opposite end of each roller frame assembly. An endless elastomeric track belt encircles a respective drive wheel, roller frame assembly, and idler wheel assembly on each side of the vehicle. A rigid support beam connects each roller frame assembly to the main frame of the vehicle. Each idler wheel assembly includes first and second self-aligning mechanisms to provide that the track belt runs true and straight. The roller frame assemblies can be spaced laterally from the vehicle, using various size spacers, to provide various gage settings of the endless track belt. During adjustment of the roller frame assemblies, a supporting arrangement supports one track roller assembly by the other track roller assembly.

CROSS REFERENCE TO RELATED APPLICATION

This is a divisional of application Ser. No. 07/950,547, filed Sep. 25,1992 and issued as U.S. Pat. No. 5,293,948 on Mar. 15, 1994.

TECHNICAL FIELD

This invention relates generally to an undercarriage assembly for a workvehicle and more particularly to an undercarriage assembly whichincludes first and second roller frame portions, a plurality of guiderollers, first and second idler wheels, an endless elastomeric belt, andfirst and second self-contained hydraulic tensioning assembliesconnected between respective first and second idler wheels and first andsecond roller frame portions.

BACKGROUND ART

Construction, earthmoving, and agricultural type work vehicles are oftenequipped with endless self-laying track chain assemblies for support andpropulsion of the vehicle. Such prior art track type vehicles, utilizingmetal track chain assemblies, are generally low speed, noisy vehiclesand work in environments which do not require any adjustment to thetrack gauge. More recently, work vehicles having endless elastomerictrack belts have been utilized to perform work tasks previouslyaccomplished by metal track equipped vehicles. The vehicles havingelastomeric track belts have many advantages over metal track vehiclesand also over wheel type work vehicles. Some of these advantages includeless weight and maintenance, lower soil compaction, lower noise levels,and the ability to travel on improved roadways.

One type of prior belted vehicle is disclosed in U.S. Pat. No.4,817,746, issued to R. J. Purcell et al. on Apr. 4, 1989. In thispatent, each of the endless elastomeric belts is driven by a pair ofelevated drive wheels and is guided and supported by a pair of largediameter idler wheels and a plurality of smaller diameter guide rollers.The idler wheels and guide rollers are supported and suspended by aplurality of links, levers, and fluid cylinders. This large number ofcomponents in the undercarriage and suspension adds complexity, weight,and cost to the vehicle.

Another type of belted vehicle having a track roller frame assembly isdisclosed in U.S. Pat. No. 4,836,318 issued to A. J. Tonsor et al. onJun. 6, 1989. This patent discloses a vehicle having a track rollerframe which is connected to the front of the vehicle by a pivot joint,and is connected to the rear of the vehicle by a collar which extendsbetween the two drive wheels. The track roller frame also has an insidesupport device which connects the roller frame to the vehicle on theinside of the drive wheels. Although this type of suspension and trackroller frame would appear to function satisfactorily for this particulartype of vehicle, it is rather complex and limits the ground clearanceunder the vehicle. The roller frame supports between the drive wheelsand to the inside of the drive wheels would also tend to collect dirtand debris.

The present invention is directed toward overcoming one or more of theproblems as set forth above.

DISCLOSURE OF THE INVENTION

In one aspect of the present invention, an undercarriage assembly for avehicle having a main frame and first and second drive axles includesfirst and second roller frame assemblies connected respectively to thedrive axles, a support beam connected to the vehicle main frame and toeach roller frame assembly, first and second self-aligning idler wheelassemblies, and first and second endless track assemblies and the idlerwheel assemblies. The undercarriage assembly further includes first andsecond track tensioning mechanisms, a first self-aligning mechanismconnecting each track tension mechanism to one of the idler wheelassemblies, and a second self-aligning mechanism connecting each trackroller frame assembly to one of the idler wheel assemblies.

Prior art belted track vehicles generally incorporate endless beltshaving guide blocks on the inner side of the belt which guide and centerthe belt as the belt rotates around the drive wheel, guide rollers, andidler wheel. Each of the wheel and roller assemblies generally include apair of spaced wheels with the space accommodating the guide blocks. Ifthe belt does not run straight, the guide blocks contact the wheels androllers, which generated excessive heat and accelerated wear.

The prior art belted track vehicles also utilize hydraulic cylinders totension the belts and provide recoil functions. The tensioningcylinders, which are supported by the track roller frames, are connectedby hydraulic lines to the vehicle hydraulic system. These lines aresubject to wear and rupture which causes contamination of the entirevehicle hydraulic system.

The subject invention provides an undercarriage assembly havingself-aligning idler wheel assemblies which adjust to properly center thedrive belt. The subject invention further provides a self-containedhydraulic tensioning ram having no hydraulic connecting lines betweenthe ram and the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic side elevational view of a vehicleincorporating the subject invention;

FIG. 2 is a diagrammatic cross-sectional view taken generally along thelines 2--2 of FIG. 1;

FIG. 3 is a diagrammatic side elevational view, partly in section, of aself-aligning mechanism of the present invention;

FIG. 4 is a diagrammatic cross-sectional view taken generally along thelines 4--4 of FIG. 3;

FIG. 5 is a diagrammatic front elevational view, partly in section, of aportion of the support beam, the vehicle frame, and the undercarriageroller frame;

FIG. 6 is a diagrammatic side elevational view, partly in section, takengenerally along the lines 6--6 of FIG. 5;

FIG. 7 is a diagrammatic top plan view, partly in section, of a reardrive wheel, a drive axle, a portion of a roller frame assembly, and theconnection between the roller frame assembly and the drive axle;

FIG. 8 is a diagrammatic top plan view, partly in section, similar toFIG. 7, with spacers between the drive wheel and the axle and betweenthe roller frame assembly and the support beam; and

FIG. 9 is a diagrammatic side elevational view of the self-containedhydraulic ram of the subject invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings, a belted track vehicle 10 has a main frame12, an engine 14, and first and second drive axles 16, 18 which arepowered by the engine 14. An undercarriage assembly 20 for the vehicleincludes first and second roller frame assemblies 22, 24, a support beam26, first and second self-aligning idler wheel assemblies 28, 30, firstand second drive wheels 32, 34, and first and second endless trackassemblies 36, 38 encircling respectively the first and second drivewheels 32, 34, the first and second roller frame assemblies 22, 24, andthe first and second idler wheel assemblies 28, 30.

Each of the track assemblies 36, 38 includes an endless elastomeric belt39 which supports and propels the vehicle. The belt 39 has a pluralityof inwardly facing guide blocks 41. The undercarriage assembly 20further includes first and second self-contained hydraulic belttensioning mechanisms 40, 42. It is to be understood that most of thecomponents of the undercarriage assembly 20 on the left hand side of thevehicle 10, as shown in FIG. 1, are duplicated and are substantiallysimilar to those components on the right hand side.

Each of the roller frame assemblies 22, 24 has first and second endportions 44, 46 and a middle portion 48, with the second end portions 46being releasably connected to a respective first and second drive axle16, 18. The support beam 26 has first and second end portions 50, 52 anda middle portion 54 which is releasably connected to the vehicle mainframe 12. The first and second end portions 50, 52 are releasablyconnected to the middle portion 48 of a respective first and secondroller frame assembly 22, 24.

Each of the idler wheel assemblies 28, 30 has a spindle 56 and first andsecond spaced wheels 58, 60 rotatably supported on the spindle 56. Eachspindle 56 includes first and second spaced apart shaft portions 61, 63,a middle portion 65, and first and second plates 67, 69 rotatablyconnected to respective first and second shaft portions 61, 63. Thewheels 58, 60 are connected to respective first and second plates 67,69. Each spindle 56 also has first and second radially extending flangeor ear portions 62, 64, with the first ear portion 62 having first andsecond spaced flanges 66, 68 which define a space 70 therebetween. Afirst self-aligning mechanism 72, including a spherical bearing assembly74, is positioned between the flanges 66, 68 and within the space 70.Each of the track tensioning mechanisms 40, 42 includes an hydraulic ramassembly 76 having a first end portion 78 connected to a respectivefirst spindle ear portion 62. A second end portion 80 of each ramassembly 76 is connected to a respective roller frame assembly 22, 24.The first self-aligning mechanism 72 serves to connect the first endportion 44 of each track tensioning mechanism 40, 42 to the first earportion 62 of each spindle 56 by way of a retaining pin 82. Theretaining pin 82 has a radially extending connecting portion 84 which isconnected to the first flange or ear portion 62.

The second ear portions 64 include third and fourth spaced flanges 86,88, and a second self-aligning mechanism 90 is positioned between andconnected to these flanges 86, 88. A means 92 for pivotally connectingthe second self-aligning mechanism 90 to the roller frame 22 includes alever member 93 and a cap member 95. The first end portion 44 of eachroller frame assembly 22, 24 has a forwardly extending nose portion 92and the second self-aligning mechanism 90 connects the nose portion 92to the second flange, or ear, portion 64 of each spindle 56. The secondself-aligning mechanism 90 serves to releasably connect each spindle 56to the first end portion 44 of each roller frame assembly 22, 24.

The second self-aligning mechanism 90 includes a universal typeapparatus 94 having a block portion 96 having first and secondconnecting portions 98, 100. The first connecting portion 98 includesfirst and second connecting pins 102, 104 and the second connectingportion 100 includes a third connecting pin 106. The third connectingpin 106 is positioned at an angle which is substantially normal to thefirst and second pins 102, 104. The third and fourth spaced flanges 86,88 are adapted to be pivotally connected to said third connecting pin106. The universal type apparatus 94 includes the lever member 93 andthe cap member 95, with the block portion 96 forming a portion of thelever member 93. The cap member 95 has a mounting portion 108 and a pinreceiving portion 110, with the mounting portion 108 being connected tothe roller frame assembly 22 by a plurality of threaded fasteners 112.The pin receiving portion 110 is adapted to receive the secondconnecting pin 104 of the universal type apparatus 94.

The lever member 93 includes a bifurcated yoke portion 114 at one endand the block portion 96 at the opposite end. The yoke portion 114 isadapted to surround the mounting portion 108 of the cap member 95. Theblock portion 96 has a bore 116 extending therethrough at an angle whichis substantially normal to the first and second connecting pins 102,104. The third connecting pin 106 is positioned within the bore 116 and,as previously noted, pivotally connects the third and fourth flanges 86,88 to the block portion 96. A securing means 118, such as acircumferential groove 120 in the pin 106 and a threaded fastener 121extending through the block portion 96, secures the pin 106 within thebore 116.

The forwardly extending nose portion 92 is adapted to receive the firstconnecting pin 102, and in combination with the cap member 95 and thesecond connecting pin 104, pivotally connects the idler wheel assembly28 to the roller frame assembly 22. A bore 122 in the extending noseportion 92, a threaded bore 124 in the pin receiving portion 110 of thecap member 95, and a threaded fastener 125 which penetrated the bore 120and engages the threaded bore 122, provides a means 126 for connectingthe extending nose portion 92 to the pin receiving portion 110.

First and second threaded fasteners 128, 130, and corresponding firstand second threaded holes 132, 134 in the yoke portion 114 of the levermember 93 provide a means for moving the yoke portion 114 laterallyrelative to the cap member 95. The threaded fasteners 128, 130 areadapted to engage an extension 136 of the roller frame assembly 22.First and second lock nuts 138, 140 engage the respective first andsecond threaded fasteners 128, 130 and the yoke portion 114 to provide ameans for locking the yoke portion 114 at a plurality of positions.

With particular reference to FIGS. 1 and 5, a means 142 is provided forsupporting the first roller frame assemble 22 by the second roller frameassembly 24 when the first roller frame assembly 22 is disconnected fromthe first drive axle 16 and from the support beam 26. The means 142includes first and second heavy walled tube sections 144, 146 connected,as by welding, to the first roller frame assembly 22, and third andfourth heavy walled tube sections 148, 150 connected to the secondroller frame assembly 24. The supporting means 142 further includes afirst bar 152 extending through the first and third tubes 144, 148 and asecond bar 154 extending through the second and fourth tubes 146, 150.The same supporting means 142 is used to support the second roller frameassembly 24 by the first roller frame 22 when the second roller frameassembly 24 is disconnected from the second drive axle 18 and from thesupport beam 26. The first and third tube sections 144, 148 aresubstantially axially aligned. The first and second bars 152, 154,extend completely across the vehicle 10 and beneath the main frame 12 toengage and extend through the respective tube sections 144, 148 and 146,150.

With particular reference to FIGS. 5, 6, 7, and 8, a means 156 isprovided for positioning each of the roller frame assemblies 22, 24 at aplurality of locations laterally spaced from the main frame 12. Thepositioning means 156 includes a plurality of first and second spacers158, 160. The first spacers 158 are adapted to be connected between thesecond end portions 46 of the roller frame assemblies 22, 24, and thedrive axles 16, 18. The second spacers 160 are adapted to be connectedbetween the middle portions 48 of the roller frame assemblies 22, 24 andthe first and second ends 50, 52 of the support beam 26. The spacers158, 160 provide adjustment of the gage setting of the endless trackassemblies 36, 38. Although only one set of spacers 158, 160 isillustrated, it is understood that a plurality of different sizes ofspacers can be used for varying the gage settings. The supporting means142 are utilized during the changing of the track gage.

First and second brackets 162, 164 releasably connect the middle portion54 of the support beam 26 to the main frame 12 of the vehicle 10. Thebrackets 162, 164 are connected to the main frame 12 by a plurality offirst threaded fasteners 166 and to the support beam 26 by a pluralityof second threaded fasteners 168. A plurality of resilient spaces 170are positioned between the support beam and the brackets 162, 164, andbetween a clamp plate 172 and the brackets 162, 164 and are compressedby the second threaded fasteners 168. This provides a resilient mountingof the support beam 26.

With particular reference to FIGS. 1 and 9, each of the track tensioningmechanisms 40, 42 includes the hydraulic ram assembly 76, an accumulator174, and a manifold block 176. The hydraulic ram assembly 76 includes arod 178 and a pressure chamber 180. The accumulator 174 is in directfluid communication with the pressure chamber 180 through the manifoldblock 176. The rod 178 includes an eye portion 182 which connects withthe first flange portion 62 of the idler assemblies 28, 30. The manifoldblock 176 includes a fill and shut-off valve assembly 184 and a bleedvalve 186. The pressure chamber 180 and accumulator 174 are initiallypressurized from a remote hydraulic source, such as the hydraulicimplement circuit of the vehicle 10. Once pressurized, the tracktensioning mechanisms 40, 42 are substantially self sustaining, sincethey are void of any hydraulic connections to the vehicle 10. One ofmore pressure seals 188, which seal on the polished surface of the rod178, prevent any appreciable fluid leakage from the pressure chamber180. If the pressure chamber ever needs recharging, the fill andshut-off valve 184 is used. The second end portions 80 of each ramassembly 76 is connected to the roller frame assemblies 22, 24 bymounting pins 192.

INDUSTRIAL APPLICABILITY

With reference to the drawings, the subject invention is particularlyuseful on agricultural type work vehicles, and more specifically on workvehicles which are supported and propelled by endless elastomeric trackbelts. It is advantageous that such vehicles have good traction, lowground pressure, low soil compaction, relatively high ground clearance,and have variable gage capabilities. The variable gage is especiallyuseful for operating the vehicle in agricultural fields having differentrow crop spacings.

The vehicle 10 is supported and propelled by an undercarriage assembly20 which includes first and second roller frame assemblies 22, 24, firstand second idler assemblies 28, 30, first and second drive wheels 32,34, and first and second endless track assemblies 36, 38. Aself-contained hydraulic belt tensioning mechanism 40, 42 is connectedat one end to the roller frame assembly 22, 24 by a pin 192, and isconnected at the opposite end to the first self-aligning mechanism 72 bythe eye portion 182. The second self-aligning mechanism 90 connects eachidler assembly 28, 30 to the roller frame assemblies 22, 24 and providespivoting of the idler assemblies 28, 30 about the third pin 106 andagainst the force of the tensioning mechanism 40, 42. The first andsecond self-aligning mechanism 72, 90 provide for self alignment of thebelt 39 on the idler assemblies 28, 30 and prevent extended contactbetween the guide blocks 41 and the wheels 58, 60.

The gage of the track belts is changed by disconnecting the first endportion 44 and the middle portion 48 of the roller frame assembly 22from the respective drive axle 16 and the support beam 26. Apredetermined spacer 158 and 160 is connected between the drive axle 16and the roller frame assembly 22 and between the support beam 26 and theroller frame assembly. This procedure is then repeated for the oppositeside of the vehicle 10 with the second roller frame assembly 24. Whilethe first roller frame assembly 22 is disconnected from the axle 16 andthe support beam 26, it is supported by the supporting means 142 and thesecond roller frame assembly 24. Likewise, when the second roller frameassembly 24 is disconnected from the axle 16 and the support beam 26, itis supported by the supporting means 142 and the first roller frameassembly 22. During adjustment of the track gage, additional mechanicalmeans are required to move the roller frame assemblies 22, 24 to theproper position along the supporting means 142.

Recoil function is provided by the tensioning mechanisms 40, 42. Ifdebris or foreign material become lodged between the idler wheelassembly 28 and the belt 39, the idler wheel assembly 28 swingsrearwardly against the tensioning mechanism 40. The rod 178 moves intothe pressure chamber 180 and forces hydraulic fluid into the accumulator174, which further compresses the gas in the accumulator 174. Once theforeign material exits the area between the idler wheel assembly 28 andthe belt 39, the force in the accumulator returns the idler wheelassembly 28 to its original position.

Other aspects, objects and advantages of this invention can be obtainedfrom a study of the drawings, the disclosure, and the appended claims.

I claim:
 1. An undercarriage assembly for a vehicle, said vehicle havinga main frame, an engine, and first and second drive axles powered bysaid engine, said undercarriage assembly comprising:first and secondroller frame assemblies, each having first and second end portions and amiddle portion, said second end portions being releasably connected to arespective first and second drive axle; means for connecting saidvehicle to said first and second roller frame assemblies; first andsecond idler wheel assemblies, each having a spindle and first andsecond spaced wheels rotatably supported on said spindle, said spindlebeing releasably connected to a first end portion of a respective rollerframe assembly, each of said spindles having first and second radiallyextending ear portions; first and second endless track assembliesencircling respectively said first and second roller frame assembliesand said first and second idler wheel assemblies; first and second tracktensioning mechanisms, each including a hydraulic ram assembly having afirst end portion connected to a respective first spindle ear portionand a second end portion connected to a respective roller frameassembly; a first self-aligning mechanism connecting the first endportion of each track tensioning mechanism to said first ear portion ofeach spindle, and a second self-aligning mechanism connecting the firstend portion of each roller frame assembly to said second ear portion ofeach spindle; and means for supporting said first roller frame assemblyby said second roller frame assembly when said first roller frameassembly is disconnected from said first drive axle and from saidconnecting means, and means for supporting said second roller frameassembly by said first roller frame assembly when said second rollerframe assembly is disconnected from said second drive axle and from saidconnecting means.
 2. An undercarriage assembly, as set forth in claim 1,wherein said supporting means include a plurality of first tubularmembers connected to said first roller frame assembly and a plurality ofsecond tubular members connected to said second roller frame assembly,each of said first tubular members being axially aligned with one ofsaid second tubular members, and a plurality of elongated bars, each barbeing adapted to extend through respective pairs of first and secondtubular members.
 3. An undercarriage assembly, as set forth in claim 1,wherein each of said track tensioning mechanism includes an hydraulicram assembly having an hydraulic pressure chamber, an accumulator, and amanifold block, said pressure chamber and said accumulator being indirect fluid communication through said manifold block.
 4. Anundercarriage assembly, as set forth in claim 1, including means forpositioning each of said roller frame assemblies at a plurality oflocations laterally spaced from said main frame.
 5. An undercarriageassembly, as set forth in claim 4, wherein said positioning meansincludes a plurality of spacers adapted to be connected between saidroller frame assemblies and said drive axle and between said rollerframe assemblies and said connecting means.
 6. An undercarriage assemblyfor a vehicle, said vehicle having a main frame, an engine, and firstand second drive axles powered by said engine, said undercarriageassembly comprising:first and second roller frame assemblies, eachhaving first and second end portions and a middle portion, said secondend portions being releasably connected to a respective first and seconddrive axle; means for connecting said vehicle to said first and secondroller frame assemblies; first and second idler wheel assemblies, eachhaving a spindle and first and second spaced wheels rotatably supportedon said spindle, said spindle being releasably connected to a first endportion of a respective roller frame assembly, each of said spindleshaving first and second radially extending ear portions; first andsecond endless track assemblies encircling respectively said first andsecond roller frame assemblies and said first and second idler wheelassemblies; first and second track tensioning mechanisms, each includinga hydraulic ram assembly having a first end portion connected to arespective first spindle ear portion and a second end portion connectedto a respective roller frame assembly, each of said track tensioningmechanism including an hydraulic ram assembly having an hydraulicpressure chamber, an accumulator, and a manifold block, said pressurechamber and said accumulator being in direct fluid communication throughsaid manifold block; and a first means for connecting the first endportion of each track tensioning mechanism to said first ear portion ofeach spindle, and a second means for connecting the first end portion ofeach roller frame assembly to said second ear portion of each spindle.7. An undercarriage assembly for a vehicle, said vehicle having a mainframe and first and second drive axles, said undercarriage assemblycomprising:first and second roller frame assemblies, each having firstand second end portions and a middle portion, said second end portionsbeing releasably connected to a respective first and second drive axle;means for connecting said vehicle to said first and second roller frameassemblies; first and second idler wheel assemblies, each having aspindle having first and second radially extending flange portions, saidfirst end portion of a respective roller frame assembly being connectedto a second flange portion; first and second endless track assembliesencircling respectively said first and second roller frame assembliesand said first and second idler wheel assemblies; first and second tracktensioning mechanism, each including a hydraulic ram assembly having afirst end portion connected to a respective first flange portion of eachspindle and a second end portion connected to a respective roller frameassembly, each of said track tensioning mechanisms including anaccumulator and a manifold block, said accumulator being in direct fluidcommunication with said hydraulic ram through said manifold block; andmeans for supporting said first and second roller frame assemblies, onesupported by the other, when one of said roller frame assemblies isdisconnected from the drive axle and from the connecting means.
 8. Anundercarriage assembly for a vehicle, said vehicle having a main frameand first and second drive axles, said undercarriage assemblycomprising:first and second roller frame assemblies, each having firstand second end portions and a middle portion, said second end portionsbeing releasably connected to a respective first and second drive axle;means for connecting said vehicle to said first and second roller frameassemblies; first and second idler wheel assemblies, each having aspindle having first and second radially extending flange portions, saidfirst end portion of a respective roller frame assembly being connectedto a second flange portion; first and second endless track assembliesencircling respectively said first and second roller frame assembliesand said first and second idler wheel assemblies; first and second tracktensioning mechanism, each including a hydraulic ram assembly having afirst end portion connected to a respective first flange portion of eachspindle and a second end portion connected to a respective roller frameassembly; and means for supporting said first and second roller frameassemblies, one supported by the other, when one of said roller frameassemblies is disconnected from the drive axle and from the connectingmeans, said supporting means including a plurality of first and secondtubular members connected respectively to said first and second rollerframe assemblies, each of said first tubular members being in axialalignment with one of said second tubular members, and a plurality ofelongated bars, each bar being adapted to extend through respectivepairs of first and second tubular members.
 9. An undercarriage assembly,as set forth in claim 8, including a plurality of spacers adapted to beconnected between said roller frame assemblies and said drive axle andbetween said roller frame assemblies and said connecting means.